In recent years, from the consideration of limited resources and environmental issues, electric vehicles in which a storage battery is mounted as a travelling energy source are gathering attention. Moreover, a charger/discharger including a main body, a cable, and a charge/discharge connector in order to charge or discharge a storage battery mounted in an electric vehicle has been proposed (for example, Document 1 (JP Pub. No. 2013-31348)).
In the main body of the charger/discharger disclosed in Document 1, an electromagnet switching device that interrupts current flowing in the cable when the value of the current is a predetermined value or higher is provided in the charge/discharge connector. Further, Document 1 also discloses a technique of supplying electric power from a storage battery to household electrical appliances.
However, the charger/discharger disclosed in Document 1 does not have a function of detecting the presence or absence of a malfunction in the electromagnet switching device provided in the charge/discharge connector. Thus, it is not possible to immediately take countermeasures such as sending an alarm notification or the like to users even when a malfunction such as weld of the electromagnet switching device in the charge/discharge connector occurs.